Insertion device positioning guidance system and method

ABSTRACT

A system and a method for an insertion device positioning guidance system comprising: an electromagnetic field generator configured to generate an electromagnetic field covering a treatment area; a plate sensor configured to be positioned within the treatment area in a location defining an orientation of a subject; a reference sensor configured to be positioned, within the treatment area, on the subject&#39;s torso, the reference sensor is configured to define a reference coordinate system representing the position and orientation of the subject&#39;s torso relative to said field generator; a registration sensor configured to mark at least a first and a second anatomic locations relative to the reference coordinate system; and a processor configured to operate said field generator, read signals obtained from said the plate sensor, said reference sensor and said registration sensor, calculate a position and orientation thereof relative to said field generator, generate a 3D anatomic map representing the torso of the subject and the first and second anatomic locations, said processor is further configured to facilitate visualization on the 3D anatomic map of a position, orientation and/or path of a tip sensor, located in a distal tip section of the insertion device, with respect to the first and second anatomic locations, independent of the subject&#39;s movement and independent of deviations in the position and/or orientation of said field generator, thus determination of a successful medical procedure is facilitated.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. patent application Ser. No.15/679,469 filed on Aug. 17, 2017, which claims priority to U.S.Provisional Patent Application No. 62/376,520 filed Aug. 18, 2016 whichis incorporated by reference as if fully set forth herein in itsentirety.

FIELD OF INVENTION

Embodiments of the disclosure relate to insertion device positioningguidance systems and methods.

BACKGROUND

Enteral feeding is often used as nutritional support in patients unableto be fed otherwise. Although many benefits are associated with earlyinitiation of enteral feeding, misplacement of feeding tubes isrelatively common and can result in patient discomfort andcomplications. Confirming the position of the tube only after it isalready inserted delays the feeding and the initiating of hydration ormedication. Bedside electromagnetic (EM) systems for guided placement ofnasoenteral feeding tubes are available and are utilized by medicalstaff during the procedure to avoid misplacement of feeding tubes. Thereis still a need, however, for reliable real-time tracking systems thatprovide enhanced accuracy for critical tool positioning during medicalprocedures.

The foregoing examples of the related art and limitations relatedtherewith are intended to be illustrative and not exclusive. Otherlimitations of the related art will become apparent to those of skill inthe art upon a reading of the specification and a study of the figures.

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with systems, tools and methods, which aremeant to be exemplary and illustrative, not limiting in scope.

One of the problems often associated with an insertion of a feeding tubeusing an electromagnetic positioning guidance system, is thatreliability is difficult to obtain in the patient environment, which istypically dynamic. For example, the patient often moves and the bed ismoved from one place to another. There is thus provided herein anelectromagnetic positioning guidance system reliably operable regardlessof the patient's movement or position and which requires no calibration.

According to some embodiments, there is provided an insertion devicepositioning guidance system comprising: an electromagnetic fieldgenerator configured to generate an electromagnetic field covering atreatment area; a plate sensor configured to be positioned within thetreatment area in a location defining an orientation of a subject(specifically, the vector perpendicular to the subject's chest); areference sensor configured to be positioned, within the treatment area,on the subject's torso, the reference sensor is configured to define areference coordinate system representing the position and orientation ofthe subject's torso relative to said field generator; a registrationsensor configured to mark at least a first and a second anatomiclocations relative to the reference coordinate system; and processingcircuitry configured to operate said field generator, read signalsobtained from the plate sensor, said reference sensor and saidregistration sensor, calculate a position and orientation thereofrelative to said field generator, said processing circuitry is furtherconfigured to generate an anatomic map, representing the torso of thesubject and the first and second anatomic locations, said processingcircuitry is further configured to facilitate visualization on the 3Danatomic map of a position, orientation and path of a tip sensor,located in a distal tip section of the insertion device, with respect tothe first and second anatomic locations, independent of the subject'smovement and independent of deviations in the position and/ororientation of said field generator, thus determination of a successfulmedical procedure is facilitated.

In some embodiments, the reference sensor is configured to be positionedon a side of the patient's torso, such that the 3D anatomic map furtherdepicts a body contour of the subject. In some embodiments, the 3Danatomic map shows a frontal upper view of the subject essentiallyparallel to the plate sensor. In some embodiments, the 3D anatomic mapshows a side view of the subject essentially perpendicular to the platesensor. In some embodiments, the 3D anatomic map shows an axial view ofthe subject.

In some embodiments, the system further comprises a monitor configuredto display the 3D map.

According to some embodiments, the term “anatomic map” as disclosedherein, may refer to one or more schematic maps, one or more 2D anatomicmaps, one or more 3D anatomic maps or any combination thereof. Accordingto some embodiments, the term “anatomic map” as disclosed herein, mayrefer to a group of maps (e.g., 2, 3, 4 or more) maps, each representinga different view (for example, frontal view, frontal upper view, sideview, axial view).

In some embodiments, the plate sensor is configured to be positionedunder the subject's upper torso and/or neck.

In some embodiments, the registration sensor is a stylus configured tobe manually operated.

In some embodiments, the insertion device is a gastroenteral tube.

In some embodiments, the first anatomic location is the suprasternalnotch, and the second anatomic location is the xiphoid process. In someembodiments, a frontal view display of the path of the gastroenteraltube relative to the first and second anatomic locations is indicativeof a successful insertion. In some embodiments, the location where thedisplayed path (in frontal view) of the gastroenteral tube crosses anaxis between the first and second anatomic locations is indicative of asuccessful insertion. In some embodiments, the actual shape of thedisplayed path of the gastroenteral tube is indicative of a successfulinsertion.

According to some embodiments, there is provided a method for guiding aninsertion device, the method comprising: utilizing an electromagneticfield generator, applying an electromagnetic field to a treatment area;positioning a plate sensor within the treatment area in a locationdefining an orientation of a subject; positioning a reference sensorwithin the treatment area, on a subject's torso, the reference sensordefines a reference coordinate system representing the position andorientation of the subject's torso relative to the field generator;utilizing a registration sensor, marking at least a first and a secondanatomic locations; utilizing processing circuitry, operating said fieldgenerator, reading signals obtained from the plate sensor, the referencesensor and the registration sensor, calculating a position andorientation thereof relative to said field generator, generating ananatomic map representing the torso of the subject and the first andsecond anatomic locations; and displaying on the anatomic map aposition, orientation and/or path of a tip sensor of the insertiondevice, with respect to the first and second anatomic locations,independent of the subject's movement and independent of deviations inthe position and/or orientation of said field generator.

In some embodiments, the method further comprises the step of displayingthe path of the distal tip section of the insertion device on theanatomic map and thus facilitates determination of a successful medicalprocedure.

In some embodiments, the positioning of the reference sensor comprisespositioning thereof on a side of the patient's torso, such that theanatomic map further depicts a body contour of the subject.

In some embodiments, the positioning of the plate sensor comprisespositioning thereof under the subject's upper torso and/or neck.

In some embodiments, the registration sensor is a manually operatedstylus.

In some embodiments, the anatomic map shows a frontal upper view of thesubject essentially parallel to the plate sensor. In some embodiments,the anatomic map shows a side view of the subject essentiallyperpendicular to the plate sensor. In some embodiments, the anatomic mapshows an axial view of the subject.

In some embodiments, the insertion device is a gastroenteral tube.

In some embodiments, the first anatomic location is the suprasternalnotch and the second anatomic location is the xiphoid process. In someembodiments, a path display of the gastroenteral tube relative to thefirst and second anatomic locations is indicative of a successfulinsertion. In some embodiments, the location where the displayed path ofthe gastroenteral tube crosses an axis between the first and secondanatomic locations is indicative of a successful insertion. In someembodiments, the actual shape of the displayed path of the gastroenteraltube is indicative of a successful insertion.

In some embodiments, the electromagnetic field generator is not in anyphysical contact with the patient. In some embodiments, theelectromagnetic field generator is designed not to be in physicalcontact with the patient. In some embodiments, the electromagnetic fieldgenerator is not designed to be in direct or indirect physical contactwith the patient.

In some embodiments, the processor/processing circuity may include twounits or two sub-units. The first is configured to control the entiretracking system (e.g., operate the field generator, read signalsobtained from the plate sensor, the reference sensor and theregistration sensor and calculate a position and orientation thereofrelative to said field generator. The second is configured to receivethe calculated position and orientation information from the firstprocessor, and use this information to generate a 3D anatomic maprepresenting the torso of the subject and the first and second anatomiclocations, and to allow visualization on the 3D anatomic map of aposition, orientation and/or path of a tip sensor with respect to thefirst and second anatomic locations, independent of the subject'smovement and independent of deviations in the position and/ororientation of the field generator.

According to some embodiments, the tip sensor, which may also bereferred to as a position sensor, is positioned at or adjacent to thedistal end of the tube/catheter/stylet and aids in determining theposition of the distal end of the tube/catheter/stylet in a patient.

The systems and methods described herein may be applied, according tosome embodiments, using sensors (e.g., position sensors) such asmagnetic field sensors, impedance-based sensors or ultrasonic sensors.According to some embodiments, the position sensor (e.g., tip sensor)may refer to an element mounted on a catheter/tube/stylet, which causesthe processing circuitry to receive signals indicative of thecoordinates of the element. The position sensor may include a receiver,which generates a position signal to a processing circuitry/control unitbased on energy received by the sensor (for example, from the fieldgenerator). According to some embodiments, the communication between thesensors and the processing unit may be wireless.

More details and features of the current invention and its embodimentsmay be found in the description and the attached drawings.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, suitable methods andmaterials are described below. In case of conflict, the patentspecification, including definitions, will control. In addition, thematerials, methods, and examples are illustrative only and not intendedto be limiting.

BRIEF DESCRIPTION OF THE FIGURES

Exemplary embodiments are illustrated in referenced figures. Dimensionsof components and features shown in the figures are generally chosen forconvenience and clarity of presentation and are not necessarily shown toscale. The figures are listed below.

FIG. 1 is a block diagram of an insertion device positioning guidancesystem, in accordance with some embodiments;

FIG. 2A schematically illustrates an insertion device positioningguidance system in a hospital setting, in accordance with someembodiments;

FIG. 2B shows an enlarged portion of the illustration of FIG. 2A, inaccordance with some embodiments;

FIG. 2C shows a side view of the illustration of FIG. 2A, in accordancewith some embodiments;

FIGS. 2D-E schematically illustrate an insertion device positioningguidance system in a hospital setting, showing anatomic locations markedusing a stylus, reference sensor and plate sensor located at differentlocations, in accordance with some embodiments;

FIG. 3A shows a view of a “live” display of placement of an insertiondevice, in accordance with some embodiments;

FIG. 3B shows a view of a “playback” display of placement of aninsertion device, in accordance with some embodiments; and

FIG. 4 is a flow chart of the steps of a method for guiding the positionof an insertion medical device, in accordance with some embodiments.

DETAILED DESCRIPTION

Disclosed herein is a system and method for guiding insertion of aninsertable medical device (e.g., a tube, such as a feeding tube). Thedisclosed system may be used as an insertion device positioning guidancesystem. The system may be used to track and indicate, in real time, thelocation of an insertion medical device during the insertion process. Asone example, the system may track and indicate the location of a tip ofa feeding tube as it is being inserted into the body of a subject.Advantageously, this makes the insertion procedure considerably easierand safer, ensuring that the tube is inserted at a correct location.

According to some embodiments, there is provided an insertion devicepositioning guidance system comprising: an electromagnetic fieldgenerator configured to generate an electromagnetic field covering atreatment area; a plate sensor configured to be positioned within thetreatment area in a location defining an orientation of a subject(specifically, the vector perpendicular to the subject's chest); areference sensor configured to be positioned, within the treatment area,on the subject's torso, the reference sensor is configured to define areference coordinate system representing the position and orientation ofthe subject's torso relative to said field generator; a registrationsensor configured to mark at least a first and a second anatomiclocations relative to the reference coordinate system; and processingcircuitry configured to operate said field generator, read signalsobtained from said the plate sensor, said reference sensor and saidregistration sensor, calculate a position and orientation thereofrelative to said field generator, generate an anatomic map representingthe torso of the subject and the first and second anatomic locations,said processor/processing circuitry is further configured to facilitatevisualization on the anatomic map of a position, orientation and path ofa tip sensor, located in a distal tip section of the insertion device,with respect to the first and second anatomic locations, independent ofthe subject's movement and independent of deviations in the positionand/or orientation of said field generator, thus determination of asuccessful medical procedure is facilitated. Optionally, the systemfurther includes a monitor configured to display the map.

A plate sensor is configured to be positioned within the treatment areain a location defining an orientation of a subject (specifically, thevector perpendicular to the subject's chest). The orientation of asubject (specifically, the vector perpendicular to the subject's chest)may be indicated by a plate sensor configured to be positioned withinthe treatment area. In a non-limiting example, the plate sensor isconfigured to be positioned under the subject's upper torso and/or neck.

A reference coordinate system representing the position and orientationof the subject's torso relative to the field generator may be indicatedby a reference sensor configured to be positioned, within the treatmentarea, on a subject's torso. The reference sensor may be positioned on aside of the patient's torso, such that the anatomic map further depictsa body contour of the subject.

The first and the second anatomic locations may be indicated by aregistration sensor configured to mark at least the first and the secondanatomic locations relative to the reference coordinate system.Optionally, the registration sensor is a stylus configured to bemanually operated. Optionally, the first anatomic location is thesuprasternal notch and the second anatomic location is the xiphoidprocess, and a path display of the gastroenteral tube relative to thefirst and second anatomic locations is indicative of a successfulinsertion.

The electromagnetic field generator may be static throughout a durationof a procedure for placing a tube within a body of a subject. In suchcases, a region covered by the electromagnetic field is static/constantthroughout the duration of a procedure for placing a tube within a bodyof a subject. Advantageously, the static electromagnetic field maycontribute to the accuracy of the display.

The anatomic map may show a frontal upper view of the subjectessentially parallel to the plate sensor and/or a side view of thesubject essentially perpendicular to the plate sensor and/or an axialview of the subject.

One example of hardware suitable for use as the abovementionedelectromagnetic tracking system, including the electromagnetic fieldgenerator and one or more of the sensors, is the Aurora® system byNorthern Digital Inc., of Ontario, Canada.

Throughout the following description, similar elements of differentembodiments of the device are referenced by element numbers differing byinteger multiples of 100. For example, an electromagnetic fieldgenerator of FIG. 1 is referenced by the number 102, and anelectromagnetic field generator of FIG. 2, which corresponds toelectromagnetic field generator 102 of FIG. 1, is referenced by thenumber 202.

Reference is now made to FIG. 1 which is a block diagram of an insertiondevice positioning guidance system 100. System 100 includes anelectromagnetic field generator 102 configured to generate anelectromagnetic field 103 a covering at least a region of interest 103 b(e.g., a treatment area such as a patient's torso), a plurality ofelectromagnetic sensors, such as sensors 104, 106, and 108, to indicatea position of a tip sensor (located in a distal tip section of theinsertion device) on an anatomical map (FIGS. 3A-B) of the region ofinterest 103 b (typically the subject's torso). System 100 furtherincludes a processor 110 configured to operate said field generator,read signals obtained from the plate sensor, the reference sensor andthe registration sensor, calculate a position and orientation thereofrelative to said field generator, and generate the anatomic maprepresenting the torso of the subject. Processor 110 is configured tofacilitate visualization on the anatomic map of the position and path ofthe tip sensor, with respect to predesignated anatomic locations,independent of the subject's movement and independent of deviations inthe position and/or orientation of field generator 102. System 100further includes a monitor 112 operatively connected to processor 110and configured to display, on the anatomic map, the positions of and/orthe path leading from the insertion device tip to the insertion site. Insome embodiments, monitor 112 may be integrated with processor 110, suchas in the case of an all-in-one computer. A determination of asuccessful medical procedure (for example, an insertion of a feedingtube to the stomach as opposed to the lungs) is thus possible.

Sensor 108 is typically a plate sensor configured to be positionedwithin the treatment area in a location defining an orientation of asubject. Optionally, the location is indicative of a subject's posture.Plate sensor 108 is optionally a 6-DOF (Degreed-of-Freedom)electromagnetic sensor. Plate sensor 108 is optionally positioned in thebed of the subject and is configured to mark the posture of the subjectby marking the positon of the bed. Alternatively, plate sensor 108 maybe attached to the subject's body. Optionally, plate sensor 108 ispositioned under the subject's back. Optionally, plate sensor 108 ispositioned under the subject's upper torso and/or neck. In case platesensor 108 is kept adjacent to the subject's back, it may indicate ifthe subject is lying, lying with his upper body partially lifted orsitting. Reference sensor 108 may be, for example, a 6-DOFelectromagnetic sensor, capable of determining 6 axes of its location(XYZ axes) and attitude (roll, yaw, and pitch) with respect to fieldgenerator 102.

Sensor 104 is typically a reference sensor configured to be positionedon a subject's torso. Reference sensor 104 is configured to define areference coordinate system representing the position and orientation ofthe subject's torso relative to the field generator. Optionally,reference sensor 104 may be attached to the skin of the patient, forexample on the side of a patient's torso such as beneath the patient'sarmpit. In such cases, the anatomic map further depicts a body contourof the subject. Reference sensor 104 may be, for example, a 6-DOFelectromagnetic sensor, capable of determining 6 axes of its location(XYZ axes) and attitude (roll, yaw, and pitch) with respect to fieldgenerator 102.

Sensor 106 is typically a registration sensor configured to bepositioned on and/or to mark at least a first and a second anatomic(thoracic) locations over the subject's body (e.g. the subject's torso).Different anatomical locations may be marked depending on the type ofprocedure used, the type of insertion medical device, etc. The markingof the anatomic location may be physical, such as attaching amarker/fiducial (such as a sticker). Alternatively, the marking of theanatomic location may be virtual, such as registering a virtualmarker/fiducial. The marking, in accordance with embodiments, mayfacilitate identification or designation of an anatomical locationwithin or on a subject's body such as, in a non-limiting example, asubject's suprasternal notch, and a subject's xiphoid process.

Optionally, registration sensor 106 is a stylus sensor configured to bemanually operated to mark at least a first and a second anatomiclocation over the subject's body identified by the operator of thestylus. The marking may be made, merely as an example, by indicating tothe software (for example, but not limited to, by pressing a GUI buttonor voice activation) once stylus sensor 106 is positioned over thedesired point on the patient's body. The marking may be communicated toand registered by processor 110.

System 100 is configured to work in conjunction with an insertionmedical device (not shown), such as a feeding tube. The insertionmedical device may include one or more sensors to allow its trackingwithin region of interest 103 b. Preferably, the sensor is located atthe tip of the insertion medical device. In such case, processor 110 andmonitor 112 are configured to compute and display position and/oradvancement of the tip of the insertion medical device between thedesignated anatomical locations leading to the insertion site/targetarea.

According to some embodiments, as used herein the terms “insertiondevice” and “insertion medical device” may refer to any device/tooladapted for insertion into a body. The insertion device may be anymedical insertion device or a medical surgical device. Non-limitingexamples of insertion medical devices include, feeding tubes, such asgastroenteral tubes (for example, nasoenteral feeding tubes),endotracheal tube, tracheostomy tube, stomach tube, catheter tubes orcricothyrotomy tube. Other examples of insertion devices are well knownin the art.

According to some embodiments, the terms “processing circuitry” and“processor” may be used interchangeably.

In some embodiments, the insertion device is a tube. In someembodiments, the tube is a feeding tube. In some embodiments, the tubeis a gastro/enteral feeding tube, such as, but not limited to, anasogastric feeding tube or a naso-enteral feeding tube. According tosome embodiments, the feeding tube may have disposed therein and/orthereon an electromagnetic sensor, for example at its distal end.

Reference is now made to FIGS. 2A-E which schematically illustrate aninsertion device positioning guidance system 200 in a hospital setting,in accordance with some embodiments. FIG. 2A schematically illustratesan insertion device positioning guidance system in a hospital setting,in accordance with some embodiments, FIG. 2B shows an enlarged portionof the illustration of FIG. 2A, in accordance with some embodiments,FIG. 2C shows a side view of the illustration of FIG. 2A, in accordancewith some embodiments and FIGS. 2D-E schematically illustrate aninsertion device positioning guidance system in a hospital setting,showing anatomic locations marked using a stylus, reference sensor (asshown in FIGS. 2A-C) and plate sensor located at different locations, inaccordance with some embodiments.

Similarily to system 100 of FIG. 1, system 200 includes anelectromagnetic field generator 202, and a plurality of electromagneticsensors 204, 206, and/or 208. Further, system 200 is configured to workin conjunction with an insertion medical device (not shown) which mayinclude one or more electromagnetic sensors configured to sense and/orinterfere with the electromagnetic field generated by field generator202. Optionally, monitor 212 of system 200 is integrated with acomputer, which corresponds to or includes processor 110 of FIG. 1.

According to some embodiments, electromagnetic field generator 202 maybe positioned at such angle and position with respect to the patient, asto enable the generated electromagnetic field to cover the external andinternal working area, or in other words, the entire upper torso (atleast from the nose area to the duodenum area). Reference sensor 204,plate sensor 208, and stylus sensor 206 are all covered under the fieldproduced by field generator 202. The tip sensor of the feeding tube isconfigured to move inside the digestive system, and its path can thus betraced. Reference sensor 204 may be attached to and/or on the skin ofthe patient, for example beneath the patient's armpit. Suitable meansfor attachment of the sensor are well known in the art such as, forexample, stickers, medical glue and the like. Reference sensor 204 mayserve to detect location (XYZ axes) and attitude (roll, yaw, and pitch)of the patient with respect to field generator 202, based on theelectromagnetic field (not shown) emitted by field generator 202.

As discussed herein, plate sensor 208 may be positioned at a locationwhich defines an orientation of a subject (or at least the orientationof the body part that is being treated). For example, if the medicalinsertion procedure involves the patient's torso, plate sensor 208 maybe positioned on the part of the patient's bed 215 parallel to thetorso, as shown in FIG. 2D. Alternatively, as shown in FIG. 2E, a platesensor 308 is inserted at least partially between the patient's back andbed 215.

Stylus sensor 206 may be manually operated to mark one or more anatomiclocations over the patient's skin. For example, FIGS. 2D and 2E show themarking of two such anatomic locations (indicated as “206 a” and “206 b”in these figures) on the patient's chest. Anatomic location 206 a ismarked over the suprasternal notch, and anatomic location 206 b ismarked over the xiphoid process. The marking may be communicated to andregistered by the computer.

Optionally, the computer receives signals of the locations and posturesof reference sensor 204, plate sensor 208, and the two marked anatomiclocations 206 a and 206 b, and computes an anatomic mark representativeof the subject's torso, thereafter the medical procedure can begin. Inthe exemplary case of guiding the insertion of a feeding tube, the tipof the feeding tube is equipped with a sensor. Optionally, the computerreceives the actual position and orientation of the sensors from asecond processor that receives the signals and calculates the sensors'locations. Optionally, the computer receives the actual position andorientation from a second processor that receives the signals from thesensors and calculates their physical location.

System 200 is operated as follows:

The electromagnetic field generator 202 is activated to apply anelectromagnetic field to the treatment area, covering the subject'storso;

Plate sensor 208/308 is positioned within the treatment area in alocation defining an orientation of a subject (or at least theorientation of the body part that is being treated), for example, on thebed beneath the subject's torso;

Reference sensor 204 is positioned within the treatment area, on asubject's torso, preferably on the side of the torso. Reference sensor204 defines a reference coordinate system representing the position andorientation of the subject's torso relative to the field generator;

Registration sensor 206 is used to mark two anatomic locations on thesubject's torso (for example, the suprasternal notch and the xiphoidprocess);

Utilizing a processor, generating an anatomic map representing the torsoand the two anatomic locations and displaying on monitor 212 theanatomic map and the position and path of the tip sensor (of the feedingtube). The path of the tip sensor may be displayed with respect to thetwo anatomic locations and/or with respect to a longitudinal axispassing between the two anatomic locations and along the center of thetorso.

Reference is now made to FIG. 3A, which shows a view of a “live” displayof placement of an insertion device, in accordance with some embodimentsand to FIG. 3B, which shows a view of a “playback” display of placementof an insertion device, in accordance with some embodiments. Suchdisplays may be presented on a monitor such as monitor 212. The leftcorner includes general information and patient's details, and in thedisplay of FIG. 3B, also playback controls.

The tip's path is schematically drawn, enabling the caregiver tovisualize the entire insertion path of the tube, until it reaches thedesired location. Optionally, and as shown in FIGS. 3A and B, an arrowis near the tip of the path, indicating the actual direction to whichthe tube is pointing. Such arrow(s) may help the user to properly insertthe tube (or better understand where and to which direction the tube ismoving). The displays of both FIGS. 3A and B show three views of thepatient's body: a frontal view shown at the top right side of themonitor, a lateral view shown at the bottom left side of the monitor,and an axial view shown at the bottom right side of the monitor. In someembodiments, different and/or additional views may be shown.

The caregiver inserting the insertion medical device can view theindications on monitor 212 while manually maneuvering the medicalimplement into the patient's body, so as to guide it to the desiredlocation in the body.

Reference is now made to FIG. 4, which is a flow chart of the steps of amethod for guiding the position of an insertion medical device, inaccordance with some embodiments. Step 420 includes application of anelectromagnetic field to a treatment area. Optionally, anelectromagnetic field generator, such as electromagnetic field generator202 of FIG. 2, is positioned such that the electromagnetic field coversthe treatment area. A plate sensor, such as plate sensor 208 of FIGS.2A-D, is positioned in a location defining an orientation of a subject(or at least the orientation of the body part that is being treated)(step 422). A reference sensor, such as reference sensor 204 of FIGS.2A-D, is positioned on a patient within the treatment area, on asubject's torso, the reference sensor defines a reference coordinatesystem representing the position and orientation of the subject's torsorelative to the field generator (step 424). Optionally, the referencesensor is positioned on a side of the patient's torso such as toindicate a body contour of the subject. At least a first and a secondanatomic location are marked by utilizing a registration sensor (step426). Optionally, a stylus sensor, such as stylus sensor 206 of FIGS.2A-D, is manually operated to mark the at least first and secondanatomic locations (e.g., 206 a and 206 b). Alternatively, one or moreregistration sensors are positioned over the at least first and secondanatomic locations. Optionally, the first anatomic location is thesuprasternal notch and the second anatomic location is the xiphoidprocess. Each of reference sensor 204, plate sensor 208, and the twomarked anatomic locations 206 a and 206 b are present within the regionof interest. Each of steps 420, 422 and 424, may be performedsimultaneously or in an interchangeable order. An anatomic maprepresentative of the subject's torso and the first and second anatomiclocations is generated by utilizing a processor (step 428). The anatomicmap may be generated based on signals received from reference sensor204, plate sensor 208, and two marked anatomic locations 206 a and 206b. A position and orientation of a tip sensor of the insertion device isdisplayed on the anatomic map, with respect to the first and secondanatomic locations, independent of the subject's movement andindependent of deviations in the position and/or orientation of thefield generator (step 430). This can be accomplished when all sensorsremain within the sensing volume of the field generator.

Optionally, the anatomic map shows a frontal upper view of the subjectessentially parallel to the plate sensor, a side view of the subjectessentially perpendicular to the plate sensor, an axial view of thesubject. Optionally, the anatomic map enables visualization of thelocation of an insertion device (having an electromagnetic sensorconfigured to sense and/or interfere with the electromagnetic fieldgenerated by the field generator) within a subject's body by computingand displaying a position of the inserted device vis-à-vis first andsecond anatomic locations 206 a and 206 b. Optionally, the computing mayinclude normalizing the position based at least on signals received fromreference sensor 204 and plate sensor 208, and obtained continuouslyand/or in real-time during the procedure.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device havinginstructions recorded thereon, and any suitable combination of theforegoing. A computer readable storage medium, as used herein, is not tobe construed as being transitory signals per se, such as radio waves orother freely propagating electromagnetic waves, electromagnetic wavespropagating through a waveguide or other transmission media (e.g., lightpulses passing through a fiber-optic cable), or electrical signalstransmitted through a wire. Rather, the computer readable storage mediumis a non-transient (i.e., not-volatile) medium.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Java, Smalltalk, C++ or the like,and conventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general-purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. A guidance system for positioning an enteral tubecomprising: an electromagnetic field generator configured to bepositioned externally to a subject's torso, said electromagnetic fieldgenerator configured to generate an electromagnetic field covering atreatment area; an enteral tube comprising an electromagnetic sensor,said electromagnetic sensor configured to sense its location and/ororientation relative to the electromagnetic field; a reference sensorconfigured to be positioned, within the treatment area, on the subject'storso, the reference sensor configured to define a reference coordinatesystem representing the position and orientation of the subject's torsorelative to said field generator, the reference sensor configured to bepositioned independently of the insertion of the enteral tube; aregistration sensor configured to mark at least a first and a secondanatomic location and/or orientation on the subject's torso; and aprocessing circuitry configured to read signals obtained from saidreference sensor and said registration sensor, and calculate anorientation of the subject relative to said field generator, basedthereon; load a predefined anatomical map representing a torso; alignthe map based on the first and a second anatomic location marked by theregistration sensor and the calculated orientation of the subject, andshow on the map a path of the enteral tube insertion with respect to thefirst and second anatomic locations; wherein the path is generatedaccording to changes in the strength of the electromagnetic field sensedby the tip sensor's during the insertion of the enteral tube.
 2. Thesystem of claim 1, further comprising a plate sensor configured to bepositioned within the treatment area in a location defining anorientation of a subject, said plate sensor configured to be positionedindependently of the insertion of the enteral tube; and wherein theprocessing circuit is further configured to read signals obtained fromand wherein calculating the orientation of the subject is further basedon the plate sensor signals.
 3. The system of claim 2, wherein saidplate sensor is configured to be positioned under or above the subject'supper torso and/or neck.
 4. The system of claim 1, wherein saidreference sensor is configured to be positioned on a side of thepatient's torso.
 5. The system of claim 1, wherein the anatomical mapshows a frontal upper view of the subject, a side view of the subject,an axial view of the subject or combinations thereof.
 6. The system ofclaim 1, further comprising a monitor configured to display the map. 7.The system of claim 1, wherein the registration sensor is incorporatedinto a tip of a stylus configured to be manually operated.
 8. The systemof claim 1, wherein the first anatomic location is the suprasternalnotch and the second anatomic location is the xiphoid process, andwherein a path display of the enteral tube relative to the first andsecond anatomic locations is indicative of a successful insertion. 9.The system of claim 1, wherein the enteral tube is a feeding tube. 10.The system of claim 1, wherein the electromagnetic sensor is positionedat a distal tip of said enteral tube.
 11. The system of claim 1, whereinthe electromagnetic sensor is a separate unit configured for beingremovably positioned within the enteral tube.
 12. A method for guidinginsertion of an enteral tube, the method comprising: utilizing anexternal electromagnetic field generator to apply an electromagneticfield covering a treatment area; positioning a reference sensor withinthe treatment area, on a subject's torso, wherein the reference sensordefines a reference coordinate system representing the orientation ofthe subject's torso relative to the field generator, wherein thereference sensor configured to be positioned independently of theinsertion of the enteral tube; marking at least a first and a secondanatomic location utilizing a registration sensor; utilizing aprocessing circuitry to: load a predefined anatomical map representing atorso; and align the map based on the first and second anatomiclocations marked by the registration sensor and the defined referencecoordinate system, inserting an enteral tube into the patient, theenteral tube comprising a tip sensor configured to sense its locationand/or orientation relative to the electromagnetic field generator; andshowing on the map a path of the enteral tube insertion; wherein thepath is generated according to changes in the strength of theelectromagnetic field sensed by the tip sensor's during the insertion ofthe enteral tube.
 13. The method of claim 12, further comprisingpositioning a plate sensor within the treatment area in a locationdefining an orientation of a subject, independently of the insertion ofthe enteral tube; and wherein the processing circuit is further utilizedto calculate an orientation of the subject relative to the fieldgenerator based at least on signal obtained from said plate sensor. 14.The method of claim 12, wherein positioning of the plate sensorcomprises positioning thereof under or above the subject's upper torsoand/or neck.
 15. The method of claim 12, wherein positioning thereference sensor comprises positioning thereof on a side of thepatient's torso.
 16. The method of claim 12, wherein the anatomical mapshows a frontal upper view of the subject, a side view of the subject,an axial view of the subject or combinations thereof.
 17. The method ofclaim 12, wherein the registration sensor is incorporated into a tip ofa manually operated stylus.
 18. The method of claim 12, wherein thefirst anatomic location is the suprasternal notch and the secondanatomic location is the xiphoid process, and wherein a path display ofthe enteral tube relative to the first and second anatomic locations isindicative of a successful insertion.
 19. The method of claim 12,wherein the enteral tube is a feeding tube.